Question

On June 4–24, 2007, the Gallup Poll asked a nationwide sample of adult Americans about their attitude toward interracial marriage. Of the 2388 adults interviewed, 77% said that they approve of marriage between whites and blacks.

a. Is this number (77%) a parameter or a statistic? Explain briefly.

b. What kind of graph would be appropriate for displaying the results of this survey—a dotplot or a bar graph? Explain briefly. (Do not create the graph.)

c. Identify the sample size in this survey.

d.i. Ignoring the sample size, what type of sampling method would need to be used for the sample to be representative of the population of all American adults?

d.ii. Why is it important for the sampling method to have the characteristic you identified in part 1 of this question?

Answer 1

(a) 77% is a statistic because it is based on a sample of size 2388. parameters are the population charisteristic.

(b) bar graph. there can be many reason like the distribution of number of Americans who approve of marriage between whites and blacks is binomial. since this random variable take discrete probability so bar graph is appropriate. 2nd we can say that data is on nominal scale so for nominal scale bar graph is appropriate.

(c) 2388

(d) (i) a random sample must be drawn to represent sampke as representative of population. so Simple random sampling is good sampling method.

(d) (ii) because if we choose sample random then the characterstic used in part 1 will be unbiased estimator of population proportion.

hii.. i am trying to provide the detailed answer to you. if you have any querry please ask by comment. please like the answer. thanks..